含裂纹载人密封舱体结构在轨失效分析方法

Failure Assessment Method for Habitable Module Structure Containing Cracks

入轨后的载人密封舱体结构存在一定程度的初始裂纹,微流星与空间碎片的撞击会使密封舱体结构产生新的裂纹损伤,密封舱体为薄壁结构,长期在轨飞行期间,在各种载荷的作用下,裂纹损伤可能导致密封舱体失效。考虑到不同的裂纹损伤来源及其转化,提出了载人密封舱体结构总体失效分析方法。首先提出了载人密封舱体结构在轨期间由裂纹损伤导致失效的两类模式及判定依据,并说明了各裂纹损伤间的转化关系;然后,说明了基于Forman模型进行舱体裂纹扩展分析的原理;最后,对某在轨飞行15年的载人密封舱结构因舱压导致的结构失效进行了分析,确定了舱体结构上的断裂失效危险部位及危险裂纹形式,并得到穿透裂纹的临界长度。

The existence of cracks in the structure of habitable module , which originates from the fabrication process , is inevitable .The impingement of micrometeoroid/orbital debris on the module in space may cause new crack damages to the main structure .In addition, main structures of habita-ble modules are usually made of thin-walled components , so due to the loads imposed by a variety of factors, the crack damage on the module structures may lead to the failure of the module .Consider-ing the different origins of crack damage and the possible transition among them , an integrated fail-ure assessment method for the habitable module structure was developed .First, two failure modes of habitable module structures and the criteria for failure assessment were proposed .Then, the method predicting the crack growth for the habitable module structure , which was based on Forman equa-tion, was presented.In the end, the failure analysis was performed for a module of 15 years’ serv-ice life, where structure failure due to pressure load was considered .The critical positions on the module structure and corresponding crack mode were identified , and the critical length of the through crack was obtained .